Ionoregulatory strategies and the role of urea in the Magadi tilapia (Alcolapia grahami)

The unique ureotelic tilapia Alcolapia grahami lives in the highly alkaline and saline waters of Lake Magadi, Kenya (pH ~10.0, alkalinity ~380 mmol·L –1 , Na + ~350 mmol·L –1 , Cl – ~110 mmol·L –1 , osmolality ~580 mosmol·kg –1 ). In 100% lake water, the Magadi tilapia maintained plasma Na + , Cl – , and osmolality at levels typical of marine teleosts and drank the medium at 8.01 ± 1.29 mL·kg –1 ·h –1 . Gill chloride cells were predominantly of …